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Title
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Monolayer 1T-LaN₂ : Dirac spin-gapless semiconductor of p-state and Chern insulator with a high Chern number
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Author
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Abstract
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| Two-dimensional transition-metal dinitrides have attracted considerable attention in recent years due to their rich magnetic properties. Here, we focus on rare-earth-metal elements and propose a monolayer of lanthanum dinitride with a 1T structural phase, 1T-LaN2. Using first-principles calculations, we systematically investigated the structure, stability, magnetism, and band structure of this material. It is a flexible and stable monolayer exhibiting a low lattice thermal conductivity, which is promising for future thermoelectric devices. The monolayer shows the ferromagnetic ground state with a spin-polarized band structure. Two linear spin-polarized bands cross at the Fermi level forming a Dirac point, which is formed by the p atomic orbitals of the N atoms, indicating that monolayer 1T-LaN2 is a Dirac spin-gapless semiconductor of p-state. When the spin-orbit coupling is taken into account, a large nontrivial indirect bandgap (86/354meV) can be opened at the Dirac point, and three chiral edge states are obtained, corresponding to a high Chern number of C=3, implying that monolayer 1T-LaN2 is a Chern insulator. Importantly, this kind of band structure is expected to occur in more monolayers of rare-earth-metal dinitride with a 1T structural phase. |
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Language
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English
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Source (journal)
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Applied physics letters / American Institute of Physics. - New York, N.Y., 1962, currens
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Publication
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New York, N.Y.
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American Institute of Physics
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2020
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ISSN
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0003-6951
[print]
1077-3118
[online]
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DOI
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10.1063/5.0023531
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Volume/pages
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117
:14
(2020)
, 6 p.
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Article Reference
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143101
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ISI
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000578551800001
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Medium
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E-only publicatie
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Full text (Publisher's DOI)
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Full text (open access)
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Full text (publisher's version - intranet only)
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